相关论文: Solar Magnetic Field Signatures in Helioseismic Sp…

The observed splittings of solar oscillation frequencies can be employed to separate the effects of internal solar rotation and to estimate the contribution from a large-scale magnetic field or any latitude-dependent thermal perturbation…

Solar oscillation frequencies change with the level of magnetic activity. Localizing subsurface magnetic field concentrations in the Sun with helioseismology will help us to understand the solar dynamo. Because the magnetic fields are not…

From a set of stellar spectropolarimetric observations, we report the detection of surface magnetic fields in a sample of four solar-type stars, namely HD 73350, HD 76151, HD 146233 (18 Sco) and HD 190771. Assuming that the observed…

According to the scheme of action of the solar dynamo, the poloidal magnetic field can be considered a source of production of the toroidal magnetic field by the solar differential rotation. From the polar magnetic field proxies, it is…

In the present work, we investigate how the large-scale magnetic field of the Sun, in its three vector components, has evolved during most of cycle 24, from 2010 Jan to 2018 Apr. To filter out the small-scale field of the Sun, present in…

Thirty-four years of WSO (Wilcox Solar Observatory) and thirteen years of SOHO/MDI (Michelson Doppler Imager on the Solar and Heliospheric Observatory) magnetograms have been studied to measure the east-west inclination angle, indicating…

Rotation of the large scale solar magnetic field has a great importance for the understanding of solar dynamic, for the search of longitidinal structure and for the study of solar-terrestrial relations. 30-year long observations taken at…

We study the physics of the solar tachocline and related MHD instabilities. We have performed 3-D MHD simulations of the solar radiative interior to check whether a fossil magnetic field is able to prevent the spread of the tachocline.…

One of the key questions in solar physics that remains to be answered concerns the strength and the distribution of the magnetic fields at the base of the convection zone. The flux tube dynamics requires that toroidal fields of strength as…

We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several…

We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated…

Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every 22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are…

The meridional circulation of the solar magnetic fields in Solar Cycles 21-24 was considered. Data from both ground-based and space observatories were used. Three types of time-latitude distributions of photospheric magnetic fields and…

Rather weak fossil magnetic fields in the radiative core can produce the solar tachocline if the field is poloidal and almost horizontal in the tachocline region, i.e. if the field is confined within the core. This particular field geometry…

The evolution of the photospheric magnetic field during the declining phase and minimum of Cycle 23 and the recent rise of Cycle 24 are compared with the behavior during previous cycles. We used longitudinal full-disk magnetograms from the…

We describe systematic changes in the centroid frequencies and the splitting coefficients as found using data from MDI on board SOHO, covering cycle 23. The data allow us to construct a seismic map of the evolving solar activity -- covering…

A new model has been proposed for magnetic field determination at different distances from the Sun during different solar cycle phases. The model depends on the observed large-scale non-polar photospheric magnetic fields and that measured…

We discuss bounds on the strength of the magnetic fields that could be buried in the radiative zone of the Sun. The field profiles and decay times are computed for all axisymmetric toroidal Ohmic decay eigenmodes with lifetimes exceeding…

Besides their own intrinsic interest, correct interpretation of solar surface magnetic field observations is crucial to our ability to describe the global magnetic structure of the solar atmosphere. Photospheric magnetograms are often used…